Answer:
a-checks and balances
Step-by-step explanation:
the only possible answer here is a. checks and balances.
The US Constitution is based on the Separation of Powers principle, which divides the government power and responsibility into the executive, the judicial and the legislative branches, and which also sets the basis for the Checks and Balances principle, a system whereby all three branches can oversee, influence, control and limit the other to prevent abuses of power and unbalance. so it can only be A